Stable field emission of single B-doped Si tips and linear current scaling of uniform tip arrays for integrated vacuum microelectronic devices

Abstract

Articles you may be interested inEffect of ballast-resistor and field-screening on electron-emission from nanodiamond emitters fabricated on micropatterned silicon pillar arrays Enhanced electron-field emission from nanodiamond ridge-structured emission arrays capped on micropatterned silicon pillars Advanced Si-based semiconductor technology is most suitable to fabricate uniform nanostructures as integrated field emitter arrays for novel vacuum electronic devices. In order to improve the field emission homogeneity and stability of p-type silicon tip arrays for pulsed sensor applications, the authors have systematically studied the influence of the fabrication parameters on the tip shape and on the specific operating conditions. Based on detailed design calculations of the field enhancement, they have fabricated two series of hexagonal arrays of B-doped Si-tips in a triangular arrangement. The first (second) type contains three (four) patches with different number of tips (1, 91, 547 and 1, 19, 1027, 4447 for the first and second type, respectively) of about 1 (2.5) lm height, $20 (20) nm apex radius, and 20 (10) lm pitch. The field emission properties of both individual tips and complete arrays were investigated with a field emission scanning microscope at a pressure of 10 À9 mbar. The current plateau of these tips typically occurs at about 10 (3) nA and around 65 (25) V/lm field level. In this carrier saturation range, single tips provide the highest current stability (<5%) and optical current switching ratio ($2.5). Fairly homogeneous emission of the tip arrays leads to an undershooting of the expected linear scaling of the mean plateau current as well as to a much improved current stability (<1%).

Toward Amp-Level Field Emission With Large-Area Arrays of Pt-Coated Self-Aligned Gated Nanoscale Tips

“…Our fabrication approach tolerates a wide variation in the CMP step compared with the methods employing CMP for defining the gate aperture [25], [39]. In those approaches, if there are nonuniformities in the thicknesses of the gate-stack or in the planarization process, the gate aperture will not be defined uniformly across the array.…”

“…Assuming R tip = 5 nm and an emitter cone angle of 30°, electric field distribution in the device was simulated by COMSOL and the emission current from the tip was estimated by integrating (1) over the tip surface for devices with different values of H tip and R ap . For larger emitter cone angles, lower electrostatic fields and emission currents are expected [25]. These simulations neglect space charge effects [26], limitation in electron supply from the Si emitter cone, and the deviation of emission current from the classical Fowler-Nordheim (FN) behavior [27].…”

Field emission from surface textured extraction facets of GaN light emitting diodes

“…As next step the FE properties of the extraction facets were investigated by a field emission scanning microscope (FESM) under ultra high vacuum conditions (p < 10 -7 Pa) [1] using the top contact of the LED structure as cathode and setting both contacts of the LED on the same potential. As shown in Fig.…”

“…In [1] we demonstrated that Si-tip arrays are good candidates to fulfill the specific requirements of various integrated vacuum microelectronic device applications, e.g. sensors, due to their excellent field emission uniformity and homogeneity.…”

“…Silicon is an opaque indirect band gap semiconductor (1.12 eV) which absorbs the complete spectrum of visible light, whereas GaN is a complete transparent direct semiconductor (3.4 eV) which absorbs light only at very short wavelengths. Due to their contrasting light absorption properties, these two materials are perfectly suitable to investigate the fundamental photoenhanced field emission effects from semiconductor surfaces [1,3]. The ability to fabricate well defined InGaN/GaN heterostructures, containing quantum-well or -dot structures allows a systematic modification of the band gap and of both electrical and optical properties.…”